Traditionally, gaseous fuel is supplied to various gas-consuming appliances at a controlled pressure. For example, current standards generally provide that gas shall be supplied to an appliance at a pressure of approximately 1/2 pound per square inch. Regulators of the prior art have functioned effectively to provide gas at such pressures from conventional gas line sources. However, special problems arise with the delivery of liquefied petroleum gas, the use of which is becoming widespread particularly in recreational vehicles.
One of the problems involved in the delivery of liquefied petroleum gas is that the pressure at the tank tends to vary widely, depending upon the temperature of the tank. For example, the pressure might vary from under 1 pound per square inch to over 100 pounds per square inch within the range of temperatures commonly encountered in different environments. Therefore, in the event of a gas supply regulator failure, traditional gas appliance regulators are not effective to reliably supply a demand flow of low pressure gas from a source of liquid petroleum gas under conditions of such variable pressure.
Conventionally, gas-burning appliances are certified for operation with gas that is supplied at a pressure of under 1 pound per square inch. If such a pressure is exceeded, considerable danger exists; and the likelihood for such an increase, as in the event of a gas supply regulator failure, is considerably greater in the use of liquefied petroleum gas. That is, a failure of the gas supply regulator may well result in the application of high pressure gas to an appliance causing the local control on the appliance to fail which may well result in fires or explosions. Accordingly, it may be seen that a considerable need exists for an improved appliance regulator for use with liquid petroleum gas supplies, which regulator will reliably and safely supply a demand quantity of low pressure gas to gas-burning appliances.
In general, the present invention is directed to an economical, safe, reliable, and convenient regulator for supplying a variable stream of gas from a variable-pressure source to a low pressure appliance. The regulator of the present invention incorporates a dual-function structural arrangement affording separate valving action for delivering gas from a source of gas at varying pressure yet with the economy and safety of a singular mechanism.